Selective immobilization of proteins guided by photo-patterned poly(vinyl alcohol) structures

AbstractThe development of “protein resistant” materials is challenging since protein hysisorption takes place on most surfaces due to van der Waals interactions, hydrogen bonding and entropy effects. In this work a new process for converting a surface resistant to protein adsorption is presented by using a photo-patternable poly(vinyl alcohol) (PVA) based film. This material minimizes effectively protein physisorption and it can be patterned through photolithography on top of any substrate. Herein the PVA-based film is patterned on top of a poly(styrene) (PS) film, in order to achieve selective protein patterning on the PS film and demonstrate the resistance of the PVA-based material to protein physisorption. The proposed methodology is expected to facilitate the fabrication of sensors and bioelectronic devices since it provides a patterning route with alignment capabilities for protein resistant-surfaces and it is based on an easy to implement process

Effect of particle size on the photochromic response of PWA/SiO2 nanocomposite

100學年度研究獎補助論文[[abstract]]A series of photochromic phosphotungstic acid (PWA)/SiO2 composites were synthesized using the sol-gel method. Depending on the feeding schedule of PWA during synthesis, the size of the formed PWA/SiO2 particles varied considerably from as small as 1.2 nm to ca. 10 nm. With decreasing silica particle size, the total contact area/interaction between SiO2 and PWA increases, as revealed by FT-IR and solid-state 29Si-NMR analyses. Particularly, when the size of PWA/SiO2 is ~1 nm, crystallization of PWA is inhibited, and PWA presents as amorphous molecular entities distributing uniformly in the SiO2 host, which is in evidence in the XRD spectroscopy and HR-TEM imaging. In contrast, substantial crystallization of PWA takes place when PWA/SiO2 particles are as large as 10 nm, in which case less amount of surface free Si-OH is available for PWA to make bonds with. Photochromism occurs activated by ultraviolet light irradiation. The rate of coloration/bleaching is found to depend strongly on the particle size of PWA/SiO2; specifically, the rate increases twice when the particle size is reduced from 10 nm to 1.2 nm.[[incitationindex]]SCI[[booktype]]紙